Fecal Occult Blood Test

Answer

Faecal Occult Blood Test

• Description

Colorectal Cancer has become a common disease affecting different individuals worldwide and is considered the third leading cause of death due to expensive treatment approaches. However, quick disclosure of colorectal cancer can decrease mortality risk (Kościelniak-Merak et al., 2018). Faecal Occult Blood Test (FOBT) is considered an essential tool for screening colorectal cancer. Lee, Pourmorady, and Laine (2020) indicate that these non-invasive, speedy, and easy-to-conduct assessments are frequently used as a point-of-care test and self-testing. The Fecal Occult Blood Test (FOBT) is considered a non-invasive approach to screen stool for blood that cannot be seen with naked eyes, known as occult blood. According to Kościelniak-Merak et al. (2018), the presence of blood in an individual’s stool indicates that there's possible bleeding happening somewhere in the digestive tract, which can be a sign or symptom of various conditions. The FOBT is also recognized as a stool occult test, hemoccult test, guaiac smear test, immunoassay FOBT, immunochemical FOB (iFOB), and Fecal Immunochemical Test (FIT).

Purpose

 The primary purpose of FOBT is to assess if an individual has an underlying condition such as colon polyps, haemorrhoids, ulcers, diverticulosis, colitis, and colorectal cancer. According to studies, these conditions can cause bleeding in the digestive tract, ending in the stool. Guo et al. (2020) indicate that FOBT is not a diagnostic test but serves as an impetus for additional evaluation.  While FOBT is used to look for blood in the stool, it does not indicate the bleeding cause source.

How it is Conducted

According to Shapiro et al. (2017), three types of FOBT are founded on different measurement approaches. These include immunochromatographic tests, chemical tests, and DNA tests. These tests are diverse in the detection approach and their susceptibility to cross-reaction and interfering aspects. Clinicians are advised to inform patients concerning contradictions. The tests cannot be conducted on patients enduring bleeding from haemorrhoids, menstruation, and bleeding from the urinary tract because of the risk of stool infection with blood from those sections, resulting in false-positive outcomes (Kościelniak-Merak et al., 2018). There are various occult blood tests, each with a distinct approach to collect and test stool. These incorporate guaiac Fecal Occult Blood testing (gFOB), Immunochemical tests (iFOB), or Fecal Immunochemical Tests (FIT) (Clark et al., 2021). The stool collection may depend on the company. Still, normally, individuals use a spoon or other equipment to obtain a stool specimen and store it in a collecting box that comes with a test case.

The collection of the box is then delivered to the doctor for FOBT. On most occasions, immunochemical testing is favoured over guaiac faecal occult blood test, given that it is extra sensitive. Moreover, it does not need any dietary restraints before specimen collection, and testing can be conducted in a random stool specimen. On the other hand, for the Guaiac faecal occult test (gFOBT), the physician provides test sheets that are utilized to obtain stool samples from various bowel actions (Guo et al., 2020). An individual collects a sample from each of two or three bowel changes in a sanitary container, normally taken on back-to-back days, and then uses an applicator stick to apply a stool smear to a specific card's distinct area return the card to a doctor. The stool specimens should be taken one day separate because colon cancer may bleed from moment to moment rather than consistently.

According to studies, there can be positive and negative results (Lee et al., 2020). An FOBT is deemed negative if there is no blood noticed in the stool samples. On the other hand, the test can be regarded as positive if blood is seen in the stool, which may require additional tests such as colonoscopy to determine the cause of the bleeding. An individual can buy faecal blood occult blood test kits at the pharmacy to conduct the test at home.

Information Gathered

Faecal Immunochemical Tests (FIT) is used to detect a human globin, a protein element of haemoglobin, using special antibodies (Kościelniak-Merak et al., 2018). The tests are primarily conducted to measure haemoglobin concentration in a stool sample and provide detailed results.

• Validity and Reliability of FOBT

Although no screening is ever 100% authentic, the FOBT has currently deemed the most publicly accessible and convenient, well-trained, equipped screening for bowel cancer. If a person conducts the FOBT after every two years, they reduce their risk of succumbing to bowel cancer by up to a third. Recent studies conducted in the U.S. indicate that iFOB tests 81% of people with invasive CRC, and gFOB detects 64.3% of CRC (Lee et al., 2020). Occult Blood Tests sensitivity for detecting neoplastic polyps is 66.7%, specificity 62%, positive predictive value 11%, and negative predictive value 94% (Lee et al., 2020). Acknowledging the necessity for a screening approach, FOBT shows a reliable and effective screening test that boards should implement in civic health systems to identify and counter colorectal cancer (CRC).

• Sensitivity, Reliability and Predictive Values

According to Kościelniak-Merak et al. (2018), the Fecal Occult Blood Test becomes an attractive alternative when assessing the existing resources. The FOBT proves to be a sensitive and specific screening approach to predicting the presence of polyps, neoplastic polyps, and adenocarcinomas. According to researches, the Fecal Occult Blood Test displays a high negative predictive value and low positive predictive value to detect benign and malignant colorectal lesions with accuracy to detect almost two out three abrasions (Kościelniak-Merak et al., 2018). Studies indicate that the FOBT alters' sensitivity from 45% to 75%, while specificity varies from 35% to 94%. The positive predictive values changes from 10% to 60%, and the negative predictive values from 97% to 99.5% (Lee et al., 2020). A high negative predictive value can assure that a patient does not have a pre-malignant or malignant lesion if the FOBT is negative.